title: Lactate dehydrogenase a expression is necessary to sustain rapid angiogenesis of pulmonary microvascular endothelium.
abstract: Angiogenesis is a fundamental property of endothelium, yet not all endothelial cells display equivalent angiogenic responses; pulmonary microvascular endothelial cells undergo rapid angiogenesis when compared to endothelial cells isolated from conduit vessels. At present it is not clear how pulmonary microvascular endothelial cells fulfill the bioenergetic demands that are necessary to sustain such rapid blood vessel formation. We have previously established that pulmonary microvascular endothelial cells utilize aerobic glycolysis to generate ATP during growth, a process that requires the expression of lactate dehydrogenase A to convert pyruvate to lactate. Here, we test the hypothesis that lactate dehydrogenase A is required for pulmonary microvascular endothelial cells to sustain rapid angiogenesis. To test this hypothesis, Tet-On and Tet-Off conditional expression systems were developed in pulmonary microvascular endothelial cells, where doxycycline is utilized to induce lactate dehydrogenase A shRNA expression. Expression of LDH-A shRNA induced a time-dependent decrease in LDH-A protein, which corresponded with a decrease in glucose consumption from the media, lactate production and cell growth; re-expression of LDH-A rescued each of these parameters. LDH-A silencing greatly reduced network formation on Matrigel in vitro, and decreased blood vessel formation in Matrigel in vivo. These findings demonstrate that LDH-A is critically important for sustaining the rapid angiogenesis of pulmonary microvascular endothelial cells.
authors.affiliation: Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America ; Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America.
authors.forename: Glenda
authors.initials: G
authors.lastname: Parra-Bonilla
authors.forename: Diego F
authors.initials: DF
authors.lastname: Alvarez
authors.forename: Mikhail
authors.initials: M
authors.lastname: Alexeyev
authors.forename: Audrey
authors.initials: A
authors.lastname: Vasauskas
authors.forename: Troy
authors.initials: T
authors.lastname: Stevens
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D003094:Collagen; D004318:Doxycycline / Q000494:pharmacology; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D000080864:Lactate Dehydrogenase 5; D007797:Laminin; D008297:Male; D055806:Microvessels / Q000166:cytology*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D011509:Proteoglycans; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats
chemical_list: D004338:Drug Combinations; D007527:Isoenzymes; D007797:Laminin; D011509:Proteoglycans; D034741:RNA, Small Interfering; C059485:matrigel; D003094:Collagen; D007770:L-Lactate Dehydrogenase; D000080864:Lactate Dehydrogenase 5; D004318:Doxycycline